What is the evacuation distance for semi-trailers?

• A. 320 feet
• B. 400 feet
• C. 1570 feet
• D. 860 feet

Answer: (C)

Evacuation distance is about how far a potentially dangerous vapor or plume could travel from a release and still keep people safe, taking into account factors like the product’s volatility, how much is released, and wind conditions. A semi-trailer can contain a large volume of material, so a leak has the potential to generate a sizable vapor cloud that could spread quickly and reach people at considerable distance. Because of that, a larger exclusion zone is required to protect bystanders and responders from toxic inhalation hazards or ignition risks.

Among the given options, the farthest distance provides the safest margin for a worst‑case release scenario from a large vehicle. This is why 1570 feet is chosen as the correct evacuation distance. The other, shorter distances could place people inside the danger zone depending on wind and the material involved.